Gas Gas EC200 Rebuild

[Hank]

And that.. is why I hate two strokes..

That sucks man!   Well, if there is a bright side, you'll have a practically new bike when you get done.   Keep us posted!

[Bogus Jim]

Yeah that sucks. Hopefully the bearing didn't spin, I guess you'll know soon enough. Check the crank runout before assembly, so you don't have to take the engine apart a third time.   

[Osnabrock]

Here we go.
I started taking the bike apart just after I got home and posted. 
Here's the result of todays work.  An empty frame and an engine in my basement.

[Osnabrock]

I'm starting the parts list for it's reassembly. 
Right now I'm hoping that the cases and crankshaft are reusable and it's just a matter of replacing a few things.
I'll pull the crank and bring it to be measured.  I also intend on getting a new connecting rod and associated bearings.  The old crank will have to be broke down and the new connecting rod pressed in. 
I'll need new gaskets and I'll replace what other bearings are in there as well. 
Like you said Hank, when I'm done I'll have a practically new bike. 
I'll need to look into measuring runout, like Bogus Jim mentioned.  I've heard of it but don't know what it's all about.
Stay tuned.

[Osnabrock]

Things aren't going so good.
I've disassembles as much as I can but am stuck with the crankshaft gear bolt.  The thing is really in there............
I've tried heat, impact wrench, penetrating oil, and everything else I can think of.   The darn thing just won't budge.  It's factory torque is somewhere around 80-90 ftlbs so it shouldn't be easy but I'm really getting frustrated. 
It's a reverse thread bolt according to the manual so I know I'm turning it the correct way.
I've sheared off a 3/8 to 1/2 inch adapter in the process and destroyed my impact wrench somehow.  Not good.
Tonight I'm going over the a friends house with the engine.  Perhaps fresh eyes and four hands will sort things out.  Wish me luck but I forsee either a sheared off bolt or a rounded of head will be the result of tonights work. 
Likely a new crank will be the outcome rather than just a rebuild. 
I'm sad and frustrated.

[Hank]

 

[Bogus Jim]

Sometimes, the problems seem to come in bunches. I hope your luck changes soon.

Maybe a pipe would work better than an impact wrench. When I was growing up, I helped my dad overhaul a Cummins diesel from one of our tractors. The main caps called for 400 ft. lbs. of torque. The air wrench we had wouldn't budge them of course, so we used a big-ass pipe to break them loose and a torque multiplier to tighten them. It was 110 degrees in the shop, and that was the day I decided I did not want to pursue diesel mechanic as a vocation.   

[plumber mike]

Bummer with a positive. You will eventually have that feeling that the bike is done and what more could go wrong. Fix a few things after that and be done. Get bored. Sell it for cheap, and move on to another questionable bike

[Osnabrock]

Last night went as predicted.  The head didn't shear off but it did round off. 
I decided to grind the head off the bolt.  Last night the shop work was done at my buddy Robert's place and all he had was a cutting wheel for his grinder so we tried to cut some hash marks in it to get it off.  I realized that it could quickly go wrong so I opted to wait until I got back home where I had a grinding wheel of my angle grinder. 
Today I started in on it.  I ground off the head of the bolt almost flush with the gear, marked the center, and started drilling.  I made a small pilot hole with a small bit and then went up on size until the bolt head came off. 
Then crank gear is now off but I need to drill out the bolt.  That's the next step.
Thanks for the words of advice and general moral support folks!

[Sportfaller]

do you have a welder? in the past when I've rounded off bolts that were uber-stuck I've welded a second bolt, bolt head, piece of rod stock, anything handy, to the bolt for extra leverage....

[Bogus Jim]

The suspense is building... 

McMaster-Carr has left hand thread metric taps, in case you need to clean up the threads. Not a cheap item, though. If you're going to have a shop press the crank together with the new rod+bearing, it's possible they would already have the correct tap.

[Osnabrock]

Good tips all.  I don't have a welder on the farm but not here in the city but I'll remember that one......
I've come out the other end with good news.
First of all, the cases separated with just a few taps from the mallet.  Secondly, one of the main bearings came out of the case with a bit of heat from the heat gun. Thirdly, the second main bearing stayed with the crank, as it should due to a bushing, and came off with a little heat from a torch.  So in a way, much of the work is done.
Now I have to get the bolt out of the crank.  I've drilled through it and have started peeling out the threads of the old bolt.  It's slow going for the moment.  It's bound to get tougher the further I get in there. 
No pictures for much of it because I was in the heat of the moment and VERY excited to be making progress. 
Tomorrow I'll likely go to the bearing house and source the bearings that I need and perhaps bring the goodies out to the machinist. 

[Osnabrock]

I looked at McMaster.  Thanks Jim.  That might be the route that I have to go because I'm having a hell of a time getting the remaining bolt threads out.
I priced out the machine work for the crankshaft.  To press in a new connecting rod will cost between $40 and $50 dollars, the connecting rod kit will cost about $60.  Likely I'll have to pay a bit extra if I'm unable to get the last bit of bolt out, if they'll do it at all.
I also found a used crank online for about $130.  I'm tempted to snatch that up and throw it in just to get through the season and have the spare done whenever I've got the time.  I know that's crazy talk though.

[Osnabrock]

This weekend I went to do some trail maintenance for the club that I belong to in Northern MN.  I rode my DRZ400 since my GasGas was on the bench.  WOW what a bike.  It had been my dirt bike before I got the GasGas.  I rode my first enduro on it and ride it around town (just got busted by the railroad police today riding in a place I shouldn't have been.) So reliable and good for most everything.

Anyway, on the topic of the rebuild.

Parts are on their way.
-----Crankshaft--------
I didn't want to deal with the remaining bolt in the crank at the moment so I bought a used crank online $105.  I don't like putting used parts in a bike but I'm going to do it this time because it's riding season and it's a used bike.  A buddy of mine recently picked up a GasGas of roughly the same vintage so it won't be so bad to have extra parts around.
----Crank bearings-----
New crank bearings ordered from Tull Bearing here in The Cities.  $26 a piece compared to $46 from GasGas.
---Gaskets and Seals----
New bottom end gaskets (except for the easy to cut ones) ordered OEM. Master bearing seals, bolts, and O-rings (OEM) $150
---Cylinder-----
New circlips and new wrist pin bearing from Dennis Kirk (CR250).  New cylinder base gasket OEM. $50
Right now I'm up to right around $350 and done mostly right.

A lot of people I talk with assume that I'd be let down by the amount of money that I've put into this bike.  I don't feel that way at all.  I feel that anytime you buy a used bike (or new for that matter) you'll be putting some amount of money into it.  Right now I probably have more money hanging off my KLR, that I bought new, than I do invested in my Gasser.  I expect them to repay the favor and haven't been let down yet.

[greatbuffalo]

I like your attitude.